Build a single-file HTML remake of Super Mario Bros 1-1
Session from fable-5.1-mario-trajectory on Hugging Face by INONONO · MIT · condensed by Coders Talk
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35msession
0interventions
GOAL
Create a single self-contained HTML file that faithfully recreates Super Mario Bros World 1-1, must be playable and bug-free.
- +0Prompt · +0Build a single-file HTML clone of Super Mario Bros 1-1 in this directory, playable and bug-free, fun.
- +6mAgent did · +6mWrote index.html from scratch: sprites drawn as pixel art, level data for World 1-1, game state machine, physics, block interactions, flagpole/level clear logic, and rendering pipeline.
- +23mAgent did · +23mSet up a headless Playwright environment (installing chromium, npm packages) since no browser was available, to script automated play tests of the game.
- +24mAgent did · +24mRan multiple scripted play tests via Playwright/node scripts checking jump velocities, coin blocks, mushroom power-ups, fireballs, and enemy kills; tuned jump physics and fixed a bug where enemy velocity was incorrectly zeroed on collision.
- +30mFail · +30mBot simulation repeatedly died falling into the same pit at x=1418, losing all lives and ending in game over across multiple pit-detection tweaks.
- +31mAgent did · +31mTraced jump/velocity data around the pit, adjusted acceleration/skid logic and shell-kick physics, then reran tests confirming the level could be cleared with score 19100.
- +32mAgent did · +32mCaptured screenshots at various stages (fireball, flag descent, level cleared, title, big-mario stairs) to visually verify rendering, then made further data fixes for decor overlap and flagpole reset, rerunning bot tests including a small-Mario-only run that also cleared with score 17800.
- +34mAgent did · +34mDid a final real-input run of the game, checked file size/line count, inspected existing README/docs/git state, confirming index.html was the only modified file relative to committed docs.
- +35mOutcome · +35mDelivered a single 58KB dependency-free index.html implementing full SMB 1-1 level layout, physics, power-ups, enemies, and flagpole/clear sequence, verified via automated Playwright bot runs clearing the level with scores up to 19100.
VERDICT
Next time I'd ask upfront for automated playtesting via a headless browser bot from the start, since that's what actually caught the physics and pit-death bugs. The fix that mattered most was tracing the exact pit death at x=1418 with frame-by-frame velocity logs and adjusting the acceleration/skid code — that's what turned repeated game-overs into a clean level clear.